Switch



p 9, 1938. 1 c. WESCHCKE 2,114,512

SWITCH Filed Apr i1 15, 1957 INVENTOR.

A TTORNEYS.

55 contact with the PM Apr. 19, 193s UNITED STATES PATENT OFFICE swrrcn out Weacheha, 8t rm. m am April 15, m1, we... 1:1,001

winvention relates toantin switchesofatypedesignedtomaintainaoontact through a certain period of movement of a movable member in one direction, and to break 5 contactthroughapredeterminedmovementof the movable memberintheoppositedirection. a

It is the object of my invention to'provide a switchwhichisadaptableforuseintheprovision .ofacircmtmakingandbreakingmeans.operable in recurrent cycles. This switch readily adapts itself for use in combination with a thermostatic element for actuation of a circuit breaking means. when thus arranged, my switch is operable for useforanydeviceinwhichadrcuitbreaker operable in recurrent cycles is desired. For example, my switch may he'used operate lighting circuits which should be closed only-during a certainperio'dofthedayto openthecircuitafter a predetermined interval; My switch may beusedforopeningthedrcuittoanyelectrically operated device such as a refrigerator, in order to provide a defrostingperiod during which the circuittothemotoroftherefrigeratorisopened at intervals. v

cycles have been provided for accomplishing the same purposeor asimilar'pm-pose to that for wllch the present switch is These former constructions, however, usually have necessitated the provision of a constantly operated motor which opensand closes a circuit at pre determined intervals. Thermostatic motors have beenpreviouslyformedtoaccmnpiishtherotation of a rotatable member. These motors, however, have previously been relatively complicated and have not been used for operation of a circiuiilt breaker through an adjmtable period of t e.

Itis apm'poseofthepresentinventiontopro- 4o vide a simple switch which is thermostatically operated and which simultaneously operates a rotatable member.which in turn actuates a re-' currently operable circuit breaker. By this means, a device for controlling a circuit may be- .45'recurrently actuatedbyadevleewhichisextremely simple and to manufacture andwhichcostsanextremelysmallamountto operate.

Itisapurposeofmyinventiontoprovidea aodeflectable thermostatic element which operates aswitcharm. Thisswitcharrnisnormallyslidablyin contact with a suitable contact plate. Upon extreme deflection of the thermostatic element,however,theswitcharmismovedomof M iateandisheidoutof contact with this plate through a'predetermined movement during which thethermostatic element is deflecting in the opposite direction. The means holding the switch am out of contact with the contact plate also acts to hold the arm in contact 5 with the plate as it deflects into extreme position, thus creating a snap action when the thermostatic element deflects sufliciently. The thermostatic element may act either by a normal rise and fallintemperature, ormaybe actuated bym' a heating element connected in the circuit controlled by theswitch arm. When arranged in this latter manner, the switch arm closes the circuit to the heating element throughout its deflection in one direction until the switch arm 15 is deflected beyond the means holding the switch arm in contact with the contact plate. In this point of the movement, the contact arm snaps out of contact with the plate and remains out of contact therewith during the return deflection of 20 the thermostatic element as this element cools. Uponreachingacertainpointinthereturndeflection, the switch arm again snaps into engagement with the contact plate again closing the circuit to the heating element, whereupon the 25 foregoing cycle is reputed.

- It is a feature of my invention to provide a rotary element .used in conjunction with theswitch arm and operated thereby during the returndeflection of the thermostatic element. It is obvious that the means holding the switch arm outofcontactwiththecontactplatemayalsobe used to hold the switch -arm in cooperable relationship with the rotary member during the sameperiodoftime,thusactingtorotafethe rotatable member a predetermined distance during each actuation of the thermostatic element.

It is a further feature of my invention that thesnapactionswitchwhichlprovidemay be 7 used in conjunction with any movable operating 40 member in place of the thermostatic element and will act in asimilarmannergtomaintain contact throughout a certain predetermined movement oftheoperatingmembenandtobreakcontact at a predetermined point of the movement of the operating member in each direction.

It is a further feature of my invention to provideacircuitbreakingmeansoperablebyaro-' tatingmembertoclose a circuitduringapredetermineddistanceofrotation,andtoopenthe 5 circuit during the remaining portion of:the rotation. InthisdeviceIincorporateameansof varyin tbetimeofcontactsothatthecircmt may be broken throinhout a longeror shorter periodoftime.

These and other objects and novel features of my Invention will be more clearly and fully set forth in the following specification and claims.

In the drawing forming a part of myspeciilcation:

Figure '1 illustrates at'op plan view of my switch with the cover removed therefrom.

Figure 2 illustrates the switch in a view similar to that of Figure 1, showing the parts in a dif-- ferent position. v Figure 3 is' an elevation view of the switch and cover therefor, as it would appear alon the line 3-4 of Figure 1.

Figure 4 is a perspective view of the thermostatic motor showing the operation thereof.

Figure 5 is a side elevation viewof' my switch with the cover removed.

Figure 6 is a perspective view of a slightly different form of switch embodying the snap action for opening and closing a circuit.

My switch A comprises a base ll, having mounted alongone side thereof ablock ll of insulating material. The shape of this block H is perhaps best shown in Figure 5 ofthe drawing. A slot I2 is cut intothe block I l near one end thereof and a strip of bimetallic material it is inserted in the slot II. The bimetallic strip I3 is held in position by the bolt ll extending through a portion of the block il from one end thereof, and terminating in a notch I! in the block ll.

A sleeve of insulating material It, such as asbestos or the like, envelops a portion of the bimetallic strip .IS, and a heating element i1 is woundabout the sleevelli. A spring am it having a downwardly extending end 20, is secured at II to the free end of the strip I3. This downwardly extending end 20 slides over a block 22 I of insulating material partially covered by a contact plate 23. An upwardly extending cam lug .24 of insulating material, projects upwardly from the block 22 adjacent the contact plate 23. The block" isseeuredto'theba'se lloftheswitchA.

. Upon deflection of. the strip II, the arm I! is carried forwardly, the downwardly extending end II slidablycontacting the contact plate 2;. The path of movement of the end 2| is obstructed by the lug It so that continued deflection of the strip It causes the end II of the arm II to slide along the plate 23 near the edge thereof, tmtil the end 2| the lug 24; During 'this movement, the'arm ll is i'iexedout or normal position" to some extent. Upon movement past the lug 24 however, the end 2| movesby force of the resil- -iency of the arm I! snapping out of contact with II will snapinto contact with the'plate l8. Thus I in bothdirectionsof movement of the'strip It a 1 contact is provided with a snap action.

Rotatably moimted ponsspindleurpmviaej a gear 20 which a-pinionfl. The

gears and lli'ajreiprevented-i'mm rotating in one direction bythe spring ratchet pawl II. The

plnionflengagesthegearflwhiehcan-iestherewith'a cam II. Thecamll and gear 2! are mounted upon a suitable spindle 3 I A spring arm" is securedin a slot in insulation block [I and is provided with a turned downend 32' adapted to engage the cam II. A supplementary spring leaf 33 provides additional spring tension without making the arm I! excessively heavy. A bearing strip. 34 is provided near the end of the spring arm I! to hold a portion of the arm 32 rigid.

A spring arm II and a supplementary spring arm 38 are slidably secured in a slot 81 in the insulation block I I. These spring arms 38 and 36 are secured to an operating push rod SI having an operating button ll of insulating material formed thereon. Vertical notches ll are formed inthe block ll adJacent the slot 31, and the arms and 38 are bulged outwardly tosome extent to spring into these notches II when the arms I! and It are in extreme positions. The. free end of the arm II is provided with a bearing member 42 which engages the bearing strip 34 on the strip 32.

The cam I. normally engages the bearing member 42 on the arm ll which contacts the bearing strip 34 on the arm I! to close the contact between the arms I! and 8!. During therotation ofthe cam 8., however, the bearing end 42 drops away from a high point 43 of the cam. II. The

end 32 of the am, however, remains in contact with -the high portion 0! the cam. thus act- .ingtoseparate the arms 32 and ll, andto break contact therebetween. The contact between the armllandthearmflremainsbrokenuntilthe end 32" of the arm 32 drops from the 1811 Mt lioithecamllbringingthearmsllandl! into contact. By maintaining the arm I! in a constant positio and by moving the arm II inwardlyasshowninlflgureloroutwardlyal shown in Figure 2, the length oi timebetween the dropping of the arm 38 from the high point of the cam II and the dropping of the end 82' l, the gear' llisrotatjed a short distance. Rob- I itselffromthegear Asmaybeseemtheexternalcircuittohe controlled extends through the wire l4 the-arms.

II and 32, and the wire 41, returning through the wire 40 to the other supply wire 45. Whether or not this external circuit is broken depends enis diagrammatically shown by small arrows in Figure 4 of the drawing.

In Figure 6 I illustrate a simple switch embodying my system of snap action. .This switch -is illustrated as having a longitudinally movable separating bar extending through Journals I. Movement of the bar." is limited by stops II. A flexible arm I! is secured to the insulating bar I! and is provided with a downwardly ex-.

tending end 53 in slidable contact with the plate N. The arm 52 slides along the plate 54 until it engages a lug 55 mounted adjacent the edge of the plate 54. The lug 55 is angularly disposed with respect to the movement of the arm I, and acts to deflect the arm 52 to one side. This deflection of the arm 52 continues until the end II thereof clears the lug II, whereupon the arm "snaps back behind the lug 55 on to the insulating block 56. A circuit between the arm 52 and the plate 54 is in this way broken. Upon return movement, of the insulating arm 49, the arm 52 engages the back surface of the lug 55 and is deflected in the opposite direction to its previous deflection until moved sufliciently to clear the lug it, whereupon this arm snaps into engagement with the contact plate 54, thus closing the circuit between this plate and the arm 52.

It may be seen that the application of a switch of this type is virtually unlimited, and that my construction may be applied to many different types of devices. With this construction, the use 0! relay is avoided, a snap action between the contacts providing a sufllciently good electrical connection to obviate the necessity thereof for most purposes.

In accordance with the patent statutes, I have described the principles of construction and operation of my switch and while I have endeavored to set forth the best embodiments thereof, 1 desire to have it understood that this is only illustrative of a means of carrying out my invention and that ovbious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

l. A thermostatic motor comprising a base, a rotatable member mounted thereon, a bimetal strip secured at one end to said base, means secured to the opposite end of said strip and movable by deflection of said strip in one direction into engagement with said-rotatable member,

and means engageable with said movable means for holding said movable means in contact with said rotatable member during a predetermined rotation of said rotatable member during deflection of said strip in the opposite direction.

2. A thermostatic motor-comprising a base, a rotatable member mounted thereon, a bimetal strip securedat one end to said base, means secured to the other end of said strip and movable upon deflction of said strip into contact with said rotatable member, means guiding said movable means to delay contact of said movable means and rotatablemeans until the strip deflects a predetermined distance, said means holding said movable means in contact with said rotatable means throughout a predetermined re-.-

a turn deflection of said strip.

- 3. A thermostatic'motor comprising a base, a

rotatable member thereupon, a bimetal strip secured at one end to said base, resilient means snap into contact with said rotatable member when released from said guiding means, said guiding mains flexing said resilient means in the opposite direction, holding said resilient means into engagement with said rotatable member for a predetermined distance and releasing said resilient means to snap said resilient means out into the normal path 'of movement of said resilient means. I

4. A thermostatic motor comprising a base, a rotatable member mounted thereupon, a bimetal strip secured at one end on said base, a dog secured to the' otherend of said strip, means preventing rotation of said rotatable member in one direction, deflection of said strip moving'said dog into engagement with'said rotatable member to rotate the same.

5. A thermostatic motor comprising a base, a rotatable member thereupon, a means laterally deflectable by a rise in temperature secured at one end to said base, a means for preventing rotation of said rotatable member in one direction, lateral deflection of said deflectable means moving said deflectable means into engagement with said rotatable member to rotate said rotatable member.

6. A thermostatic motor comprising a. base, a rotatable member mounted thereupon, a laterally deflectable member on said base deflected by a rise in temperature, a dog engageable withsaid rotatable member mounted on said deflectable member and operable to rotate said rotatable member, a contact plate, means on said dog 'slidable over said contact plate during the time said dog is out of contact with said rotatable member,

a heating element adjacent said deflectable memher, and a circuit extending through said contact plate, said dog, said heating element and a suitable source of current supply; to energize said element when said dog is out of engagement I with said rotatable member.

'1. A thermostatic motor comprising a base, a rotatable member mounted for rotation with respect thereto, a deflectable member deflectable by heat secured at one end tosaid base, means on the other end of said deflectable member engageable with said rotatable member to rotate the same upon deflection, contact means engageable with said engageable means during the time said engageable means is out of engagement with said rotatable means, a heating element adjacent said deflectable means, and a circuit through said engageable means, said contact means and said means engaged by said engageable means during a portion of its movement, a contact plate engaged by said engageable means throughout the remaining portion of the movement of said ongageable means, a heating. element'adjacent said 15 deflectable member, and a circuit thrcugh'said' contact plate, said engageable member, and said heating element to close the circuit to said heating element when said enzageable means is outof contact with said rotatable member,

9. A switch comprising a movable element movable between two extreme positions, a resilient secured to said movable element, a bearing plate slldabl'y enmeable with said resilient arm including a contact plate and an insulating'portion, a'cam lug engageable with said arm to flex said resilifint arm, said lug holding said arm in contact th said contact plate for a predetermined movement of said movable element in one direction, and out of contact with said contact plate for a predetermined movement of said movable element in the other direction.

10. A switch comprising a reciprocable member movable between two extreme positions, a flexible an arm conductive of electricity secured to said ,re-

ciprocable member. a contact plate upon which aua'sm said flexible arm is slidably cnsagcd, said contact plate including a conductive portion and a nonconductive portion and cam means in the path oisaid arm,saidoamholdingsaidarminengagement with said contact portion flexing said arm until said arm. is moved out oi engagement with said cam, whereupon said arm flexes quickly onto said non-conductive portion.

member.

CARL WESCHCKE. 

